Snap switch



Oct. 424, 1950 CHARBQNNEAU 2,526,850

SNAP SWITCH Filed Jan. 20, 1947 Patented Oct. 24, 1950 SNAP SWITCH I Allan P.Oharbonneau,Wauwatoaa,Wia.,assignor to Cutler-Hammer, Inc., Milwaukee, Wis., a

corporation of Delaware Application January 20, 1947, Serial No. 723,185 7 Claims. (Cl. 200-78).

' This invention relates to snap switches and is .For example, it has been found that it is usually possible to manipulate the actuating mechanism of the switch in such a manner as to effect slow opening of the switch contacts. Also it has been found that if the actuating mechanism is operated by a slow moving force, suiflcient contact pressure is not maintained to prevent arcing up to the time the contacts are moved into open position.

v The present invention has among its objects to provide a snap switch having an improved leaf spring operating mechanism which overcomes the aforementioned objections.

Another object is to provide an improved snap switch of the aforesaid type which is exceedingly simple, compact and rugged in construction,

positive and reliable in operation and which can be readily manufactured and assembled at low cost.

Various other objects and advantages of the invention will hereinafter appear.

The accompanying drawing illustrates certain embodiments of the invention which will now be described, it being understood that the embodiments illustrated are susceptible of various modifications without departing from the spirit and scope of the appended claims.

In the drawing,

Figure. 1 is a longitudinal sectional view of a switch embodying the invention, the contact mechanism thereof being illustrated in one extreme circuit controlling position;

Fig. 2 is a similar view illustrating the contact mechanism in an opposite extreme position;

Fig. 3 is a plan view of the leaf spring contact element illustrated in Figs. 1 and 2;

Fig. 4 is a sectional view on line H of Fig. 1;

Figs. 5 and 6 are side elevational views of a modified form of snap switch mechanism embodying the invention, and

Fig. 7 is a plan view of the leaf spring contact element employed in the switch illustrated in l igs. 5 and 6.

Referring to Fig. 1, the same illustrates the invention in one form as applied to a snap action switch having a movable bridging contact element I which is mounted within an enclosing casing 2 comprising two elongated molded insulating members I and l which are arranged one above the other and are secured together adjacent opposite ends by a pair of rivets 5. The opposing faces of casing members 3 and 4 are provided with end to end recesses forming a rectangular opening 8 for receiving contact element i, and said contact element is provided with two pairs of cooperating stationary contacts 1-1 and 8-4, the former pair being mounted within opening 8 adjacent opposite ends of casing member I, and the latter being mounted within said opening adjacent opposite ends of casing member 4. Also the casing members are provided with alined openings for receiving a reciprocable operating member 9associated with contact element I.

More specifically, each of the stationary contacts I and 8 is provided with a, terminal portion i0 which extends through an opening in its associated casing member and is bent over to engage the outer face thereof. Bridging contact element i comprises an elongated leaf spring of rectangular shape having contact extensions I2 formed on opposite ends thereof. Said leaf spring is slotted to provide a pair of spaced parallel side arms "-43 which extend between the contact projections l2, and a pair of U-shaped flipper arms i4'l4 which are disposed in opposed relation between said side arms. The open ends of flipper arms I 4i4 are connected to the side arms iI-i3 by connecting portions i5ii and said flipper arms are slotted to provide a pair of oppositely disposed operating arms i6-I3 which extend inwardly from the closed ends of said flipper arms.

The inner ends of operating arms l6 are spaced apart to receive an enlarged shank portion l8 of rectangular shape on operating member 9. This shank portion has V-shaped notches formed on opposite sides thereof for receiving the opposing ends of operating arms i6 and is of such width that said operating arms are subjected to compressive forces which effect bowing thereof with respect to their associated flipper arms I. Operating member 9 is normall maintained in the position shown in Fig. 1 by a bow spring I! which is interposed between casing member I and the shank portion I8. Also the closed ends of flipper arms H-H are normally held in engagement with a pair of stops 20-20 formed on casing member 4 and are movable upwardly into engagement with a pair of stops 2l-2l formed on casing member 3.

With operating element 9 in the normal position shown in Fig. l the operating arms i6l5 are bowed upwardly with respect to flipper arms ll-Il to bias the outer ends of said flipper arms downwardly into engagement with their associated stops 2020. Also said flipper arms are bent downwardly with respect to the side arms iI-II so that said side arms are stressed downwardly to yieldingly maintain the contact portions I 2-42 in engagement with their associated stationary contacts 8-4.

Upon initial downward movement of operating member I out of normal position the inner ends of operating arms it are moved downwardly with respect to flipper arms ll--ll to subiect said flipper arms to an increased biasing force which tends to move the inner ends thereof downwardly from the positions shown in Pig. 1. Side arms "-13 are thus subjected to an increased downward stress to increase the pmsure of contact portions l2-l2 on their associated stationary contacts -8. This increased contact pressure is maintained until the inner ends or operating arms lt-lt are moved into a position wherein the same are substantially in alinement with the connecting portions l-l 5 on the inner ends of flipper arms ll-M. At this point the stresses in side arms l3|3 efl'ect upward movemen of the inner ends of flipper arms llil across the inner ends of operating arms lilt. The compressive i'orcu in operating arms it then act to effect snap movement of flipper arms l4 upwardly into engagement with their associated stops 2i--2I.

Contact element l is then positioned as shown in Fig. 2, the operating arms l6 thereof being bowed downwardly with respect to their associated flipper arms I and said flipper arms being bent upwardly with respect to the side arms It. The side arms I: are thus stressed in an upward direction to hold contact portions i2 in engagement with their associated stationary contacts 1.

Upon release of operating member 9 the same is returned to normal position under the action of spring I! and during such return movement the aforedescribed operation of contact element l is reversed to return said contact element with a snap movement into the position shown in Pig. 1. In other words, upon initial return movement of operating member 9 from the position shown in Fig. 2 the inner ends of operating arms l6-i6 are moved upwardly to subject the flipper arms to an increased biasing force which tends to move the inner ends thereof upwardly beyond the position shown in Fig. 2.to thereby subject the side arms I! to increased upward stress. The pressure of contact portions l2l2 on stationary contacts 1-1 is thus increased and maintained until the inner ends of operating arms "-4! are moved upwardly into a position wherein the same are substantially in alinement with the inner ends of flipper arms "-14. At this point the stresses in side arms |3-|3 eiiect quick downward movement 01' the inner ends of flipper arms I 4-44 across the inner ends of operating arms lt-le to effect return snap movement of contact element I into the position shown in Fig. 1. From the foregoing it will be seen that the above described, construction aflfords advantages particularly desired in a snap switch, namely that the actuating means is practically free of friction, that good contact pressure is maintained up to the point of snap-over with the result that chattering of the contacts is avoided, and that it is impossible to move the operating arms I into a dead center position with respect to the flipper arms H without snap-over oi the contact element I. As is apparent, either of the sets of stationary contacts 1! or 8-8 may be omitted if desired.

- Referring now to Figs. 5, 6 and "l, the same illustrate a modified embodiment of the invention including a movable contact element 23 having' one end mounted upon a flxed terminal plate 24 and its opposite end movable between a pair 01' cooperating stationary contacts 2| and 2.. The stationary contacts 2' and 2! may be mounted within one end oi! an enclosing cad! inthemannerillustratedinl'ig. Landtheterminal plate 24 may be moimted adjacent the opposite end or such casing. Contact element 28 has a biasing spring 21 associated therewith and is movable against the action or said spring by a push button operating member 2!.

As illustrated in Fig. '7, contact element 28 comprises an elongated leaf spring which is slotted to provide a pair of spaced parallel side arms 2!-2! which are connected by an end contact portion 20 and also by a U-sha'ped flippl' arm 3| having its closed end located adjacent said contact portion. Also said contact element is slotted to provide an operating arm 82 which 8 located between the side arms 22 and is omnected at one end to the closed end o flipp: arm 3|. Side arms 29-20 are flxed to termini plate 24 by a pair of binding screws 82. Also operating arm 22 is flxed to said terminal plate by a rivet 34 in a position wherein the same is subjected to a compressive force which eflectl bowing thereof with respect to flipper arm ll. Spring 21 engages the under side of operathz arm 32 at a point removed from terminal plate 24 and push button member 28 engages the upp: side of said operating arm at a point opposite said spring.

' Operating arm 32 is normally held in the position shown in Fig. 5 under the action of spring 21 so that the same is bowed upwardly with respect to the flipper arms 2 to bias the free end of said flipper arm downwardly with respect to side arms 28. Said side arms are thus stressed in a downward direction to maintain contact portion 30 in engagement with its cooperating stationary contact 26.

During initial downward movement oi operating member 28 out of normal position operating arm 32 tends to move the free end of flipper arm 3| downwardly with respect to side arms 2! to increase the pressure of contact portion ii on its associated stationary contact 25. This increased contact pressure is maintained until operating arm 32 is moved substantially into a dead center position with respect to flipper arm Ii. point the open end 01' flipper arm 3| is moved upwardly by the stressed side arms 29 into a position wherein operating arm 32 assumes a downwardly bowed position with respect to said flipper arm. vFlipper arm iii and side arms 2! are thus snapped upwardly into the position shown in Fig. 6 to move contact portion 30 into engagement with its associated stationary contact 2|.

Upon release 01' operating member 2a the above described operation of contact element 23 is reversed. In other words, the operating arm I! is moved upwardly under the action of spring 21 and during initial upward movement of said operating arm out of the position shown in Fig. 6 the free end 01' flipper arm 3| tends to move upwardly with respect to side arms 2! to increase the pressure of contact portion 30 on its associated stationary contact 28. Upon upward movement of operating arm 32 into a dead center position with respect to flipper arm 3| the open end of said flipper arm is moved downwardly by the stressed side arms is into a position wherein said operating arm assumes an upwardly bowed position with respect to said flipper arm. Side arms 29 are then moved with a snap action into the position shown in Fig. 5 for reengagement At this closed end thereof toward the open end of said contact arm, said operating arm being stressed and being movable in opposite directions into bowed biasing positions on opposite sides 01' the plane of said flipper arm to efiect snap movement of said contact arm in opposite directions between given extreme circuit controlling positions'through the medium of said flipper arm.

2. In a snap action switch, a movable contact element comprising a leaf spring punching formed to provide a U-shaped contact arm, a iJ-shaped flipper arm extending in the same direction as said contact arm and having its extremities connected to the side legs of said contact arm, and an operating arm formed integrally with said flipper arm and extending from the closed end thereof toward the open end of said contact arm, means for supporting said contact element 'and for stressing said operating arm to effect bowing thereof with respect to said flipper arm, and means for moving said operating arm in opposite directions between bowed biasing positions on opposite sides of the plane of said flipper arm to effect snap movement of said contact arm in opposite directions between given extreme circuit controlling positions through the medium of said flipper arm.

3. In a snap action switch, a movable contact element comprising a flat leaf spring punching formed to provide a contact arm, an operating arm and a flipper arm, said flipper arm being connected at one end to said contact arm and the other end being free to move with respect to I said contact arm, and said operating arm being integrally connected to the free end of said flipper arm and extending toward the opposite end thereof, and means for supporting said contact element and for holding the operating arm thereof in longitudinal compression to effect bowing thereof with respect to said flipper arm, said operating arm being movable with a snap actionin opposite directions between bowed biasing positions on opposite sides of the plane of said flipper arm to effect snap movement of said contact arm in opposite directions between given extreme circuit controlling positions through the medium of said flipper arm.

4. A snap switch comprising an insulating base, a U-shaped contact member mounted upon said base, said contact member having side legs and an end contact portion movable in opposite direactions between given extreme circuit controlling positions and having leaf spring operating parts including an operating arm and a flipper arm, said flipper arm being connected at one end to said side legs of said contact member, and the other end thereof being free to move with respect to said contact member and extending toward the end contact portion thereof, and said operating arm being integrally connected to the free end of said flipper arm and extending toward the connected end thereof, and means associated with said base for holding said operating arm in longitudinal compression to eflect bowing thereof with respect to said flipper arm and to also effect movement of said operating arm in opposite directions between bowed biasing positions on opposite sides of the plane of said flipper arm for snap movement of the end contact portion of said contact member in opposite directions between said extreme circuit controlling positions through the medium of said flipper arm.

5. In a snap action switch, a movable bridging contact element comprising a flat leaf spring punching formed to provide two end contact portions, side arms connecting said contact portions,

two U-shaped flipper arms having their open ends connected to the mid-portion of said side arms and having their closed ends extending in the direction of said contact portions, and an op erating arm for each flipper arm, said operating arms each extending inwardly from the closed end of their associated flipper arm and being integrally connected therewith.

6. In a snap action switch, a movable bridging contact element comprising a flat leaf spring punching formed to provide end contact portions, side arms connecting said end contact portions, U-shaped flipper arms having their open ends connected to the mid-portion of said side arms, and an operating arm extending inwardly from the closed end of each of said flipper arms toward the open ends thereof, and an operating member therefor for insertion between and connection with the opposed ends of said operating arms, said operating member being of sufficient thickness to effect bowing of said operating arms with respect to said flipper arms.

7. A snap switch comprising an insulating base, a bridging contact member having two side arms connecting its end contact portions, a pair of oppositely disposed U-shaped flipper arms positioned between said side arms, said flipper arms having their open ends connected to the midportion of said side arms and having their closed ends extending in the direction of said contact portions, an operating arm for each of said flipper arms, said operating arms being connected to the closed ends of said flipper arms and extending inwardly therefrom, an actuating member positioned between the inner ends of said operating arms and in operable engagement therewith, said actuating member being of suflilcient thickness to effect bowing of said operating arms with respect to said flipper arms, and a pair of stops on both sides of said contact member, said stops being positioned for abutting engagement with the closed ends of said flipper arms when said contact member is in opposite extreme positions.

ALLAN PQCHARBONNEAU.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS 

